Yarn changing means for circular knitting machines



Oct; 13, 1931. A KENT 1,827,660

YARN CHANGING MEANS FOR CIRCULAR KNITTING MACHINES Filed Oct. 3. 1929 4 Sheets-Sheet l Y 4] 17 28a INVENTOR z zw fms /dw A. w. KENT Oct. 13, 1931.

YARN C HANGING MEANS FOR CIRCULAR KNITTING MACHINES 4 Sheets-Sheet 2 Filed Oct. 3, 1929 Oct. 13, 1931.

A. W. KENT YARN CHANGING MEANS FOR CIRCULAR KNITTING MACHINES Filed Oct. 5, 1929 '4 Sheets-Sheet 3 /N W. N TOR Oct. 13, w NT 1,827,660

YARN CHANGING MEANS FOR CIRCULAR KNITTING MACHINES V Filed Oct. 5, 1929 4 Sheets-Sheet 4 Fig. 6.

Patented Oct. 13, 1931 UNITED STATES PATENT OFFICE ALFRED WOODWARD KENT, or LEICESTER, ENGLAND, AssIeNoE. To WILLIAM srmns LIMITED, or LEICESTER, ENGLAND, A BRITISH COMPANY YARN CHANGING MEANS FOR CIRCULAR KNITTDN'G MACHINES Application filed October 3,1929, Serial No. 397,032, and in Great Britain October 11, 1928.

This invention relates to yarn changing means for circular knitting machines and its object is to provide, mainly, though not exclusively, in circular rib knitting machines of 5 the superposed needle cylinder type employ- 'ing double-ended needles, an improved form and arrangement of mechanism for roducing horizontal strips or equivalent e ects in the knitted fabric.

To enable the invention to be clearly un-. derstood, a practical embodiment is hereinafter described, by way of example, with reference to the accompanying drawings.

In the drawings I Figure 1 is a sectional elevation of such example, as applied to a superposed needle cylinder knitting machine.

' Figure 2 is a sectional elevation of part of the actuating means for the yarn changing 0 device and the bobbin carrier.

' Figure 3 is a plan of the arrangement shown below the line III-III in Figure 1.

Figure 4 is a sectional plan view taken on line IVIV of Figure 1.

5 Figures 5 and 6 are detail views hereinafter particularly referred to, and

Figure 7 is a plan view of an alternative form of mechanism for operating the bobbin carrier.

y Figure 6 is drawn to a larger scale than Figures 1 to 4 and 7, and Figure 5 is drawn to an enlarged scale.

Referring to the drawings, the said embodiment is illustratedas applied to a circular seamless hosiery knitting machine of the superposed rotary needle cylinder type, op-

erating with rotar motion, for knitting the leg and foot portlons of hose or half-hose and with rotary reciprocator motion for )knitting theheel and toe poc ets, so much only of the machine being shown as will make clear the connection of the invention therewith. The machine includes upper and lower needle cylinders 18 e ui ped with s double-ended independently shda le needles and rotatable within stationary cam boxes (1. and 6 carried respectively by top and bottom plates 33 and 17, the latter being supported by a stand or frame 0. The construction and operation of the machine is generally similar to that described in the specification of William Spiers Patent No. 1,210,866, and moreover, being well known, need not be further described herein.

Hitherto, diificulty has been encountered in designing, for a machine of the type aforesaid, automatic horizontal striping means of a comparatively simple, compact and eiiicient form for introducing a multiplicity of striping yarns, one after another, to the needles with certainty, owing to the limited amount of space between the opposing ends of the needle cylinders 18. The primary purpose of the invention is to overcome this difiiculty, and consequently the invention is mainly intended for application to circular knitting machines of the type in question without however being limited in this respect.

The invention consists of yarn changing means which. include a rotary carrier equipped with a number of yarn feeders and adapted for rotation intermittently by pattern controlled means to bring the respective yarn feeders into position one after an-- other for feeding the yarns directly to the needles.

One embodiment of the invention, for application to a latch needle knitting machine, is characterised by the feature that each of the yarn feeders is constructed and arranged so as to present a run of the yarn to the needles in proximity to the knitting point in such a position that it is entered between the hooks and the closing latches. The yarn is inserted between the needle'hooks and closing latches, which latter by their closing movement draw the yarn into the hooks or at any rate prevent its escape from. the hooks.

To achieve this result each yarn feeder I mounted so that the amount of space oobobbin carrier, and a heavy impact may be caused upon arresting the rotation, assuming the requisite movement to be efiected in a single quick step.

The present invention includes an arrangement designed to obviate these disadvantages, and accordingly comprehends the combination with the rotary yarn changing device aforesaid of an independent bobbin carriage and means whereby when a yarn change takes lace the bobbin carriage is rotated in conjunction with and to'the same extent as the rotary device but at a lower speed, or mechanism which operate respectively to impart initial. movement, to the carnage and to complete said movement, it being understood that in either case the bobbin carriage is rotated over the same angular advance as the yarn change device. The two units are also independently constructed and cupied thereby in the machine is reduced to a mimmum.

According to one embodiment of the invention the yarn feeders are movably arranged in the rotary carrier andmeans are provided for moving said feeders into and out of the active positions. Yarn trapping and severing devices suitably controlled are associated with each yarn feeder, the operation thereof preferably being such that the withdrawn yarn is not trapped and severed until the yarn substituted therefor has been taken by the needles.

Associated with the yarn changing device is a rotary bobbin carriage, and, in the preferred construction and arrangement, the mechanism employed to rotate the yarn changing device is controlled by or from the same mechanism which controls the rotation of the carriage. For example, the rotary device may be rotated intermittently by the pawl and ratchet mechanism, the movements of which are controlled by a lever or equivalent in turn controlled by pattern mechanism, said lever or equivalent also controlling the action of mechanism, which may include a snail cam or the like and a clawker or parted to the bobbin carriage over the same angular advance as the rotar device.

According to the illustratlv example of the invention, Figures 1 to 6, there is provided a disc 1 furnished with a series of radial guideways 2, e. g. twelve, for the reception of a corresponding number of slidable yarn feeders. Each feeder consists of a substantially T-shaped member 3, the head 3a of which is formed with a throat 4 and an adjacent projection 5. The tail 3b of the 'T-member slides in the guideway 2. Mounted on the discbetween the yarn feeders are a corresponding number of pivoted trapping and severing devices 6, 7 the arrangement being that each feeder has its associ- 3 is furnished with a butt 11 ated trapping and severing element located adjacent to the aforesaid projection as shown in Figure 3. The yarn 8 for each feeder is passed from the bobbin (not shown) by way of a tensioning device. hereinafter referred to, through a fixed guide 9 and the throat 4, in front of the projection 5 and into the trapper 6. The projection 5 has a groove 5a which the yarn enters as each guide approaches the operative position the arrange, ment being such that a length of yarn is held more or less taut between said throat and the projection as represented at X in Figure 3, or presentation substantially tangentially to the needles 10. Each of the am feeders 5 tted with a roller 12, and there is fixed below the rotary disc, a plate 13 formed with a groove cam 14 in which the aforesaid roller works. The major part of the groove is concentric with 8 the disc 1 but opposite to the feeding point it deviates outwards to the extent necessary to project a guide to the operative position, and then returns. Thus at each movement of the disc the feeder previously in operathe feeding position the extremity thereof is 1' brought into close proximity to the needles 10 so that the aforesaid length of yarn is presented substantially tangentially thereto and, as represented in Figure 5, is entered between -the hooks and the closinglatches of those 1' needles which are descending to draw loops. As the needles engage the length of yarn the .end thereof is pulled out of the trapper which may be opened at this stage.

Each of the yarn cutters 7 is positively 11 Opened and closed, as required, by a cam 19 formed on a disc 20 fixed on the axle 15. The corresponding trapper is normally closed by a spring 21 and is opened by the cutter when this is opened, for which purpose the trapper 12 is furnished with a'projection 22 under which the cutter is located. The aforesaid cam 19 is located so that as one feeder comes into feeding position the cutter and trapper associated with the preceding feeder are held 15 open for a short time, i. e. until a few of the needles have taken both yarns, following which said cutter and trapper are operated to sever and trap the withdrawn yarn.

A hooked member 23 (Figure 6) is pivotally mounted on the latch guard A so that the hooked end 23a thereof engages with the outgoing yarn 8a and holds it up to the needles until the incoming feeder takes up its position This ensures that both yarns 1 are taken together by a few needles as aforesaid by preventing the outgoing yarn from being drawn away from the needles too soon. As the incoming feeder takes up the feeding position it engages the hooked member and by depressing same against the action of its spring holds it inoperative until the next gages with the guideways 2. The lever is connected by a link 26 and a bell-crank lever 27 with a push rod 28 which is located adjacent to, but normally held out of contact with, a lever 29 constantly oscillated by a cam 30. The rod 28 is held out of contact with the lever 29 by a pivoted lever 31 operated by a pivoted member d engaged at required intervals by dogs 6 on the pattern chain. 7 to release-the rod 28, said rod being furnished with a notch 28a for engagement with a roller 29a on the lever 29 when released. Upon release of thepush rod 28 it is operated by said lever 29 so that the pawl is actuated with the result previously explained. A back stop detent-32 engages a guideway 2 and prevents free rotation of the disc after each movement by the pawl.

Mounted above the disc 1 on the top plate 33 is a bearing 34 for a bobbin carriage constituted by a rotary sleeve formed in two parts 35, 35a inserted in opposite sides of the bearing and connected together by screws (not shown), and radial arms 36 fixed in the part 35 of, the sleeve for the reception of the bobbins (not shown). The part 35 has ratchet teeth 37 thereon for engagement with a clawker 38 or equivalent normally idle but direction being effected by spring action. The snail cam 39 imparts a comparatively slow and steady movement to the bobbin carrier, said movement being over the same angular advance but slower than that imparted to the disc 1 by the cam 30 as will be appreciated by comparing the two cams, for which purpose see Figure 2.

According to an alternative arrangement (Figure 7) the ratchet teeth 37 a are engaged by a clawker 48 or equivalent connected by a bell-crank lever 49 and a link to a lug 27a on the aforesaid lever 27. Above the top plate 33 is a pawl 51 eccentrically mounted on a driven shaft 52 so as to be constantly reciprocated. This pawl also engages the ratchet cording to the tooth arrangement adopted, so

' operable, when required, by a snail cam 39 acting through a lever 40 and a push rod 41. The cam rotates constantly and the rod 41 is prevented from operation by the lever 40 until a yarn change occurs, by means controlled by the aforesaid lever -31. These means comprise a picoted locking lever 42.

one end 42a of-which is adapted normally to enter a notch 41a in the push rod 41 (see Figures 2 and 4) to hold it in the inoperative position. clined or bevelled for engagement with a pin 43 carried by the lever 31. When the lever 31 is moved by the member d the pin 43 by' action on the inclined end of the lever 42 moves the latter out of engagement with the notch 41a in the push rod, thus allowing the latter to rise, under spring action, for actuation by the lever 40. The push rod 41 is connected by a link 44 to a bell-crank lever 45 fulcrumed in the top late'- 33 and connected to the clawker 38. e lever 40 engages a The other end 42?) of the lever is in roller 47 on the push rod to depress the latter, the movement of said push rod in the other that the complete movement of the carrier is over the same angular distance as that of the disc 1. Following this movement the pawl 51 again reciprocates idly upon the tip of the next long tooth.

The part 35a carries a series of yarn tensionin devices i. e. one for each arn radially arranged and each consistin of a plunger 53 fitted with a disc 54 and sli able in a sleeve 55 also provided with a disc 56, the yarn being passed between the discs which are normally held closed. These devices serve to keep the yarns suitably taut for presentation to the needles. At or near the feeding point a device 57 (Figure 1) is provided whereby each tensioning device is opened'to free the yarn brought into the active position. When the yarn is pulled by the needles the device 57 is actuated so that the upper end thereof engages the opposing punger 53 to open the tensioning device, as represented in Figure 1. The finger 57 may also serve as a take-up during reciprocating knitting.

The various yarns pass from the bobbins through holes 58, 59 formed longitudinally through the two parts 35, 35a, then through the tensioning devices to the fixed guides 9, and from there to thethroats 4 in the feeders 3. Said feeders register with a slot or gap 60 in the latch guard A as each comes into the feeding position, the object being to enable the feeder to approach as closely as possible to the needles.

Means may be provided for supplying a splicing yarn in conjunction with any one of the yarns supplied through the medium of the rotary changing device. Such means may include a pivoted trough 61 or equivalent v and a trapping and severing device 62 operable under pattern control to carry the splicing yarn into engagement with the main yarn. 1

Any one or more of the yarn feeders in the rotarycarrier may be used to feed a plurality of yarns in plating relation particularly for rib work in order to produce crossplating efi'ects.

The bobbin carriage may be arranged somewhat eccentrically relatively to the disc 1, so that as each yarn approaches the feeding position, any undesirable slackness may be taken u y The aforesaid yarn changing means enable a variety of yarns to be supplied to, and definitely or regularly taken by, the needles, so that, according to the number of threads employed and the intervals at which the yarns are changed, horizontal striping effects, with or without cross plating effects, in great variety and of a particularly pleasing character can be readily produced.

An important feature of the invention is the provision of, rotary yarn changing means whereby the yarns are introduced to the needles so as to be taken directly thereby, the invention thereby being distinguished from previously proposed arrangements wherein auxiliary devices such as sinker-like elements or brushes operated in proximity to the feeding point so as to catch the yarns and cause same to be taken by the needles as the feeders approached the feeding point.

In the arrangement previously described With reference to} the drawings, when a yarn change occurs, and just before the changing movement is completed, the ingoing yarn is entered between the hooks and closing latches or is engaged by the latches of those needles which are descending to draw loops and knock over, and it is found desirable to provide for a slight pause in the movement at this point so that the ingoing yarn is definitely taken by several needles before the outgoing yarn is severed. To this end the cam 30 is provided with a rest or dwell 30a whereby the operative movement of the lever 29 is arrested momentarily, at the time required. The final movement of the lever 29 completes the rotation of the yarn changing device and causes the trapping and severing means associated with the outgoing feeder to operate upon the corresponding yarn.

. What I claim then is 1. In a circular knitting machine a series of independent needles, yarn changing means comprising a rotary feeder carrier arranged outside the needle circle, a number of yarn feeders individually movable radially on said carrier, yarn engaging members associated and movable with said feeders respectively, means for rotating the carrier to bring the feeders into feeding position as required, means for advancing each feeder and the associated member as they approach the feeding posit-ion whereby a length of yarn held at separated points is carried to the needles and laid transversely to the stems below the hooks, and means for retracting the feeder and member upon leaving the feeding position.

2. In a circular knitting machine, a series of independent slidable latch needles, yarn changing means comprising a rotary feeder carrier arranged outside the needle circle, a number of yarn feeders individually movable radially on said carrier, yarn engaging members associated and movable with said feeders respectively, means for rotatingthe carrier to bring the feeders into feeding position as required, means for advancing each feeder and the associated member as they approach the feeding position whereby a length of yarn held at separated points is carried to the needles and laid transversely to the stems be-. tween, the hooks and the latches of those needles which are descending to draw loops, and means for retracting the feeder and member upon leaving the feeding position.

3. In a circular knitting machine, a series of independent slidable needles, yarn changing means comprising a rotary feeder carrier, a series of independent yarn feeders each having a feed hole and an adjacent integral projection and slidable radially on the carrier, means for rotating the carrier to bring the feeders into feeding position as required, means for advancing each feeder and the associated member as they approach the feeding position whereby a length of yarn held at septransversely to the stems below the hooks, and means for retracting the feeder and member upon leaving the feeding position.

4. In a circular knitting machine, a series of independent slidable latch needles, yarn v changing means comprising a rotary feeder carrier, a series of independent yarn feeders each having a feed hole and an adjacent integral projection and slidable radially on the carrier, means for rotating the carrier to bring the feeders into feeding position as required, means for advancing each feeder and the associated member as they approach the feeding position whereby a length of yarn held at separated points is carried'to the advancing each feeder and the associated member as they approach the feeding position, whereby a length of yarn held at separated points is carried to the needles and laid transversely to the stem below the hooks, means for retracting the feeder and'memher upon leaving the feeding position, yarn cutting and trapping means operable tosever and trap the yarn withdrawn from knitting when a change occurs, and means-for positively operating the yarn cutting and trapping means.

6. In a circular knitting machine, a series of independent slidable latch needles, yarn changing means comprising a rotary feeder carrler, a number of yarn-feeders individually slidable radially on the carrier, each feeder having a feed hole'and an adjacent integral yarn engaging projection, means for rotating the carrier to bring the feeders and associated members into the feeding position successively as required, means for, advancing each feeder and the projection-upon their approach to the feeding position, whereby a length of yarn held between the feed hole and projection is laid transversely to the needle stem between the hooks and the latches of those needles which are descending to draw loops, yarn cutting and trapping means associated with each of the feeders for cutting and holding the corresponding yarn upon withdrawal of same from knitting, and means for positively operating the cutting and trapbelow the hooks, means for retracting the feeder and member upon leaving the feedlng posltion, a rotary bobbin carriage mounted entirely independently of the feeder carrier but rotatable in conjunction therewith,

. having a feed hole and an adjacent integralduring a yarn change, over the same angular advance but at a slower speed for the purpose described.

8. In a circular knitting machine a series of independent slidable needles, yarn changing means comprising a rotary feeder carr1er, a serles of lnd'ependent yarn feeders each projection and slidable radially on the carrier, means for rotating the carrier to bring the feeders into feeding position as required, means for advancing each feeder and the associated member as they approach the feeding position whereby a length of yarn held at separated points is carried to the needles and laid transversely to the stems below the hooks, means for retracting the feeder and member upon leaving the feeding position, arotary bobbin carriage mounted entirely independently of the feeder carrier but rotatable in conjunction therewith, during a yarn change over the same angular advance but at a slower speed, for the purpose described.

9. In a circular knitting machine a series of independent needles, yarn changing means comprising a rotary feeder carrier arranged outside the needle circle, a number of yarn feeders individually movable radially on said carrier, yarn engaging members associated and movable with said feeders respectively, means for rotatin the carrier to bring the means for advancing each feeder and the associated member as they approach the feeding position whereby a length of yarn held at separated points is carried to the needles and laid transversely to the stems below the hooks, means for retracting the feeder and member upon leaving the feeding position,

yarn cutting and trapping means operable to sever and trap the yarn withdrawn from knitting when a' change occurs, means for positively operating the yarn cutting and trapping means, and a rotary bobbin carriage mounted independently of the feeder carrier but rotatable in conjunction therewith, during a yarn change, over the same angular advance but at a slower speed, for the purpose described.

10. In a circular knitting machine a series of independent needles, yarn changing means comprising a rotary feeder carrier arranged outside the needle circle, a number of yarn feeders individually movable radially on said carrier, yarn engaging members associated and movable with said feeders respectively, mechanism for rotating the carrier to bring the feeders into feeding position as required, means for advancing each feeder and the as sociated member as they approach the feeding position whereby a length of yarn held at separated points is carried to the needles and laid transversely to the stems below the hooks, means for retracting the feeder and member upon leaving the feeding positlon, a rotary bobbin carriage mounted entirely independently of the feeder carrier but rotatable in conjunction therewith during a yarn change, mechanism for rotating the carriage over the same angular advance as but at a slower speed than the feeder carrier, and means for controlling both of the aforesaid mechanisms and consequently the movements of the feeder carrier'and bobbin carriage.

11. In a circular knitting machine a series ofindependent needles, yarn changing means comprising'a rotary feeder carrier arranged outside the needle circle, a number of yarn feeders individually movable radially on said carrier, yarn engaging members associated and movable with said feeders respectively, mechanism for rotating the carrier to bring the feeders into feeding position as required, means for advancing each feeder and the associated member as they approach the feeding position whereby a length of yarn held at separated points is"'c'arried to the needles and laid transversely to the stems below the hooks, means for retracting the feeder and member upon leaving the feeding position,. a rotary bobbin carriage mounted entirely independently of the feeder carrier but rotatable in conjunction therewith and over the same angular advance during a yarn change, mechanism for initially rotating the carriage, mechanism for completing the rotation of said carriage over the same angular advance as the feeder carrier, and means for controlling the aforesaid mechanisms and consequently the movements of the feeder carrier and bobbin carriage.

In testimony whereof I aflix my signature.

ALFRED WOODWARD KENT. 

